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* RE: perf, x86: Disable PEBS on SandyBridge chips
@ 2012-02-17 12:39 Maarten Lankhorst
  2012-02-17 15:12 ` Peter Zijlstra
  0 siblings, 1 reply; 5+ messages in thread
From: Maarten Lankhorst @ 2012-02-17 12:39 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: x86, LKML

Hey Peter,

Why is PEBS disabled? If I look at the intel_clovertown_quirks I can see 
why it's disabled for that cpu, but the sandy bridge one lacks any kind 
of clarification or information on why, or how I can learn more.

Cheers,
Maarten

^ permalink raw reply	[flat|nested] 5+ messages in thread

* RE: perf, x86: Disable PEBS on SandyBridge chips
  2012-02-17 12:39 perf, x86: Disable PEBS on SandyBridge chips Maarten Lankhorst
@ 2012-02-17 15:12 ` Peter Zijlstra
  2012-02-17 21:40   ` H. Peter Anvin
  0 siblings, 1 reply; 5+ messages in thread
From: Peter Zijlstra @ 2012-02-17 15:12 UTC (permalink / raw)
  To: Maarten Lankhorst; +Cc: x86, LKML, H. Peter Anvin, Stephane Eranian

On Fri, 2012-02-17 at 13:39 +0100, Maarten Lankhorst wrote:
> Hey Peter,
> 
> Why is PEBS disabled? If I look at the intel_clovertown_quirks I can see 
> why it's disabled for that cpu, but the sandy bridge one lacks any kind 
> of clarification or information on why, or how I can learn more.

hpa, could you get the official Intel answer on this?

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: perf, x86: Disable PEBS on SandyBridge chips
  2012-02-17 15:12 ` Peter Zijlstra
@ 2012-02-17 21:40   ` H. Peter Anvin
  2012-02-17 22:08     ` David Ahern
  0 siblings, 1 reply; 5+ messages in thread
From: H. Peter Anvin @ 2012-02-17 21:40 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: Maarten Lankhorst, x86, LKML, Stephane Eranian

On 02/17/2012 07:12 AM, Peter Zijlstra wrote:
> On Fri, 2012-02-17 at 13:39 +0100, Maarten Lankhorst wrote:
>> Hey Peter,
>>
>> Why is PEBS disabled? If I look at the intel_clovertown_quirks I can see
>> why it's disabled for that cpu, but the sandy bridge one lacks any kind
>> of clarification or information on why, or how I can learn more.
>
> hpa, could you get the official Intel answer on this?

*Where* is PEBS disabled?

	-hpa


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: perf, x86: Disable PEBS on SandyBridge chips
  2012-02-17 21:40   ` H. Peter Anvin
@ 2012-02-17 22:08     ` David Ahern
  2012-02-17 22:12       ` H. Peter Anvin
  0 siblings, 1 reply; 5+ messages in thread
From: David Ahern @ 2012-02-17 22:08 UTC (permalink / raw)
  To: H. Peter Anvin
  Cc: Peter Zijlstra, Maarten Lankhorst, x86, LKML, Stephane Eranian

On 2/17/12 2:40 PM, H. Peter Anvin wrote:
> On 02/17/2012 07:12 AM, Peter Zijlstra wrote:
>> On Fri, 2012-02-17 at 13:39 +0100, Maarten Lankhorst wrote:
>>> Hey Peter,
>>>
>>> Why is PEBS disabled? If I look at the intel_clovertown_quirks I can see
>>> why it's disabled for that cpu, but the sandy bridge one lacks any kind
>>> of clarification or information on why, or how I can learn more.
>>
>> hpa, could you get the official Intel answer on this?
>
> *Where* is PEBS disabled?

arch/x86/kernel/cpu/perf_event_intel.c,
intel_sandybridge_quirk()

David

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: perf, x86: Disable PEBS on SandyBridge chips
  2012-02-17 22:08     ` David Ahern
@ 2012-02-17 22:12       ` H. Peter Anvin
  0 siblings, 0 replies; 5+ messages in thread
From: H. Peter Anvin @ 2012-02-17 22:12 UTC (permalink / raw)
  To: David Ahern
  Cc: Peter Zijlstra, Maarten Lankhorst, x86, LKML, Stephane Eranian

On 02/17/2012 02:08 PM, David Ahern wrote:
> On 2/17/12 2:40 PM, H. Peter Anvin wrote:
>> On 02/17/2012 07:12 AM, Peter Zijlstra wrote:
>>> On Fri, 2012-02-17 at 13:39 +0100, Maarten Lankhorst wrote:
>>>> Hey Peter,
>>>>
>>>> Why is PEBS disabled? If I look at the intel_clovertown_quirks I can
>>>> see
>>>> why it's disabled for that cpu, but the sandy bridge one lacks any kind
>>>> of clarification or information on why, or how I can learn more.
>>>
>>> hpa, could you get the official Intel answer on this?
>>
>> *Where* is PEBS disabled?
>
> arch/x86/kernel/cpu/perf_event_intel.c,
> intel_sandybridge_quirk()
>

OK, this is Peter's patch and I don't think I was involved with it... I 
need more of a pointer to be able to track this down.

	-hpa



^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2012-02-17 22:12 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-02-17 12:39 perf, x86: Disable PEBS on SandyBridge chips Maarten Lankhorst
2012-02-17 15:12 ` Peter Zijlstra
2012-02-17 21:40   ` H. Peter Anvin
2012-02-17 22:08     ` David Ahern
2012-02-17 22:12       ` H. Peter Anvin

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